Australia’s huge nuclear dilemma

Conventional military tactics may not be enough for Australia’s defence. Image: Supplied

THE 2026 Lowy Institute Poll reflects an Australia uneasy about its place in the world.

More than half the country feels unsafe, only one in five trust the leader of our most important ally to act responsibly in the world, and 35 per cent believe the United States would not come to Australia’s defence if it were attacked – up from 25 per cent seven years ago.

This is a nation anxious about its security, so anxious that a strategic taboo looks to be under scrutiny: an Australian nuclear weapon.

The number of Australians who are “strongly against” this notion has dropped ten points from 2022.

But while nuclear weapons may appear to be the ultimate deterrent, a nuclear capability would not make Australia safer. In fact, it would have the opposite effect.

While it is highly premature to discuss how Australia would acquire and use a nuclear weapon, given the level of anxiety this poll indicates, it is worth thinking about how such a capability would affect Australia’s strategic position.

An Australian nuclear weapon would be an alternative, not a complement, to its alliance with the United States. Washington’s nuclear umbrella – the promise of “extended deterrence” to its allies – has acted as a tool. It is a lack of trust in this umbrella that is eroding the nuclear taboo for Australia today, as it did in the 1960s.

For Australia to even consider a nuclear weapons program, its trust in the US alliance would need to have disintegrated. This would likely be the result of a withdrawal or at least a substantial drawdown of US forces in the region and a consequent cession of strategic leadership to China.

Under those circumstances, China would have an interest in preventing Australia from acquiring nuclear weapons. A nuclear weapons program takes time, and if discovered is intensely destabilising.

Given the enhancement of China’s long-range strike capabilities, any state seeking to acquire nuclear weapons would find itself threatened by China’s conventional weapons. Iran’s nuclear weapons program demonstrates this in no uncertain terms.

If, against those odds, Australia was able to develop a nuclear weapon and delivery systems without intervention, it would face a different problem: cost.

Nuclear weapons can deter major war but not limited conflict.

Nuclear weapons and their delivery systems are some of the most complex pieces of technology humanity has ever produced. Due to their destructive power, they must also be rigorously safeguarded. All this requires cash. The most relevant comparison for Australia would be the UK, with its relatively small nuclear deterrent force. In FY 2024-25, the United Kingdom’s Defence Nuclear Enterprise (DNE) consumed 18 per cent of its defence budget, or £10.0 billion.

That’s nearly $21 billion – greater than the funding for the Royal Australian Navy’s capabilities, sustainment, and nuclear-powered submarine program combined. Given the staggering costs, Australia would not be able to maintain the ADF as currently constituted and operate a credible and independent nuclear deterrent.

If Australia chose to accept this trade-off, yet another problem would emerge. Yes, a nuclear program would deter an invasion of the Australian continent, but its strategic effect would be fundamentally passive. A nuclear weapon can only function as a deterrent. It cannot serve a constabulary, diplomatic or military role (like a navy, for instance.

Australia does not have an infinite treasury. The cost of pursuing nuclear weapons would mean less investment in the ADF’s conventional capabilities, abrogating any intention to shape Australia’s strategic circumstances. This would be a departure from every iteration of defence policy since Federation.

A nuclear weapon is also no guarantee of stability. Nuclear weapons can deter major war but not limited conflict. Indeed, while they can preserve high-level stability, they may make low-level or peripheral conflict more likely. This is the so-called stability-instability paradox.

The Cold War offers many examples, from Vietnam to Afghanistan to Angola. A low-level conflict in the Indonesian archipelago would have a direct effect on Australian security, as would one on the Southeast Asian mainland. Unrest in countries such as Timor-Leste or Solomon Islands would also rightly concern Australia. An Australian nuclear program would hollow out existing military capabilities, so a nuclear-armed Australia would not be better equipped to deal with these kinds of issues.

Finally, an Australian nuclear weapon would likely spur other states to acquire their own. This might give the appearance of stability, but also sharply raises mutual threat perceptions, the costs of miscalculation, as well as the possibility of a nuclear weapon falling into the hands of a non-state actor.

On the surface, the softening attitudes to nuclear weapons shown by this year’s Lowy Poll might make sense as a response to an increasingly unsafe world. But far from making Australia safer, a nuclear weapons program would make it more vulnerable, more isolated, and less able to deal with the many different challenges of the 21st century.